Air-brake automatic bleeder valve



l.July 24, 195] E, BENOIT 2,561,607

AIR BRAKE AUTOIVIATIG BLEEDER VALVE Filed Feb. 14, 1948 3035659 l Y ig:

Inventor l .1 I mil A- 13 'eaffel )wif 361/1 45 57 al By Wmmw Patented` July 24, 195

y `S TATES l(IFFICPE I 2,561,607V N nffmtnsmnm AUTOMATIC nnaDERfvAnvE Quebec, Canada Application February 14,21948, Serial No.1'8,367 ,In Canada May26,a1!47 3 Claims. (cineos-70) o '.The fpresent invention .relates to a valve arrangement and, `more particularly, an automatic-:bleedervalve.usedin connection with railwway air brakes; which is provided withprotection against bleeding the air Vreservoir of runaway` cars. A .:Irn railway yards, among themanyrservicing operations required on thefair Vbrakesofrailway .carsfthere is .a bleedingl of the. individual car air 1 reservoirs necessary ,before the cars orcoaches ,-can be shunted. Irlhis manual bleeding of air `tanks on eachcaL-consumesra greatamount of Vtime-.andrequires thealmost exclusive. services of `rseveral `operators .-who could .be otherwise em- ,ployed elsewhere.

i ;.,Again, in a system. of `air brakes provided with .automatic bleeding means, it is .necessary to ensure that a sudden rand accidental `uncoupling @of themaingair.supplypipessuch as occurs, for example, inthefcase-of lrunawaycars, willfnot .-cause automatic `draining .of the reservoirs of y,the uncoupled cars, and thus render their .air brake system helpless.

. .Thefpresent invention -hasfbeen conceived to decrease the yamount of.time and labourconjzsumed :by shunting-.operations, and to protect Vagainstaccidental draining of `a cars air-system.

.,Consequently, theuman object of the ,inven- -ftionresides in the 4provision of means, provided in conjunction with railway air brake-equipment,

)for automatically .bleeding 4the auxiliary `reserivoirs `of a itrainmponrremoving the .pressure in -,themain airline prior to uncoupling.

:Another .object .is the provision of automatic '.:rbleeding meansof-thefcharacter described,.which contains means to protect the air brake'system I,.clf :a .train from accidental debilitation` or @drainage lAnother :object resides in `the provision of .fmeans :of the character described, which are applicable to :existing equipment.

kA still further `object contemplates the `pro- `vision of .automatic air bleeding means of the character i described operable only when aminilmum brake pipevpressure has been reached.

Finally, xstill Aan important object relates to means of the character described, which `would vdue simple, reliable in .operation and relatively inexpensive. Other objects fandadvantages i of the invention y,twill become apparent `as ,the description pro- -g1`.SSS.

-As.an@examplewandforpurposesl of illustration non ly, .a possible :embodiment-,of the` invention is fshown in Lthe-Jannexed-drawing wherein:

2 l Figure .1--is1 aperspective view., of some elements of @an air zbra'kefsystem Wthwhich the meansoi fthe `invention are ,-immediately.' associated,

` .Rianne .2 .is .a zsectional-felevation of the ,invention when the system is in normaloperation, i Eig-ureisaimilar sectional elevationqoffthe .protectivemeansofthe invention whenoperative .cwingtto accidental uncouplina 4 p,

Figure 4 is a perspective-.viewof thevalverdisc, .and

.Figure 5 isLa plan ofthe valve seat against .which the-.disc normally rests. K

`In the .drawing wherein similar reference characters :represent :corresponding `Darts `lthroughout, a simplied and somewhat y.scheimatic-showng (Figure 1).has.been.made.to represent the essential elementsof -afreghtcanair .l brakesystemandato illustrate-the relation of the @present valve means thereto. The air brake 20 hcylinder,1thenis,indicated .by `the letter ,.A, this `,cylinder.having amormalltypethree-.way valve B associated withitand coupled inturnto .the brake ,pipe .This ,pipe .C conducts .the main vsupply of compressed air and. is` provided Withan 25 yangle. cock .Dat each end: .of` the car, from .which hOSB COUDIIIgSEgIead `toadjoining cars. .Each car is ,also 1provided with `an..auxiliaryreservoir F, which isconnected.to.-and supplied by thevvalve .Bsbyrmeans ofipipingthus enabling operationof the brake cylinder. evenwhenthe main airqsupply is cut off.

l.For shunting operations,` it .is .necessary to :.drain off the pressure from. `reservoir .F in Order `to llfirevent .locking` of nthe brakeby this pressure. rThe present-invention, denotedgenerallybyl, ,is secured tothe auxiliary reservoir, and communipates with itas w11.be,pointedout. .Theinvenltionalsois-,zcoupled Joy means of v.pipe I .withfthe manubrake pipe C, and `.the .automatic .bleeding V.meansrof .the inventionis adapted to .operate when .the .air ,pressure .in `the .main '.brake lpipe `.falls below .a `.predetermined amount.

lFigure 2 .shows .the .parts 4of y.the invention .iin detail. ,Alboxelike .casing B-.enclosesthe whole, .and Vthe base `plate .of this frame .is bolted .to ,the treservoir .through thegasket. `Inthe drawing, tthe invention is1s'hownsecuredto .the .top of res- ...ervoir .but,.as `willbe pointed. outlater', `it will Operate.equally .well .when .aiiixed underneath `.the reservoir.

.Casingiiencloses a chamber .|0,. at theendspf which .are respectively, the .automatic .i bleeding .means Y,G and .the `:protectivemeans ;.P. The air i pressure in chamber .1,0, .in :normaloperatiom the same ,as .thatof .thei reservoir F. and the. brake pipe C, and this pressure is supplied from the latter through the protective means P.

Briefly, means P comprises a vertical cylindrically bored block integral with casing 8 and having interior-threaded ends. `Similarly-threaded interchangeable fittings Il and I2 having central bores are inserted at each end, and each of these bores is :in turn threaded at its outer end. One of these fittings II is adjacent to the casing of reservoir F, and a plug I3 is screwed into this fitting. At the upper end of the block the coupling IlI from pipe 1 is screwed into fitting I2.

Between fittings II and I2, a disc valve I6 is slidable in the block, this valve consisting of the disc I1 mounted medially between the spiders I8 on the spider shaft I9 (see Figure 4)'. The spiders are guided by the interior bores of the fittings, and the disc is limited in its travel by a valve seat abutting from the inner end of each fitting. The seat on' fitting I2 has a continu- ',ous machined surface against which the disc may be tightly pressed. The seat 2| of fitting II (see Figure 5) has radial slots through which 'air may pass even when the disc rests against this valve seat.

Without considering further the operation of means P at present, it suffices to say that normally this valve provides communication between brake pipe C and chamber I0.

The automotive bleeding means C consists primarily of a pressure-operated piston valve. This valve is enclosed in a cylinder which juts out into the chamber I9 and at the opposite end has a threaded flange 26 by which it is inserted into place in a horizontal bore through casing 8. A

plug 21 is screwed into place outside ilange 26 and holds the cylinder rigid.

At the end inside the chamber, the cylinder has an aperture 28, whilst at the ilange end, an offset Inside the chamber I0, the cylinder has a port 32 through its casing. From this port, a removably secured tube 33 communicates with the res- `ervoir'through apertures in the base plate of casl ing 8, the gasket, and the reservoir casing.

The piston 34, in the cylinder, has a spring 35 located between itself and the face of plug 21. Thus the piston is controlled by the pressure of the spring at one end, and the air pressure of i chamber I0 `at the other.

In operation, the air pressure existing in chamber I0 (and the brake pipe) acts behind the pisv'ton to push it towards the plug 21 thereby comj pressing spring 35 and shutting off port 32 and the communication between reservoir and passage 29 (see Figure 2); So long as a pressure exists in the brake pipe'sufficient to so compress the spring, 1 the valve will remain in the position shown in Figure 2 and air will remain stored in the auxiliary v reservoir for automatic brake application as usual.

When, however, the pressure in the brake pipes is gradually reduced to a minimum all along the train the coiled spring will push the piston away from the plug 21, thereby opening the port 32 and allowing communication between the auxiliary g reservoir and the passage to the atmosphere. Consequently the stored air is free to escape and the entire system is released, the brakes being L rendered inoperative. This bleeder valve obviousf bleeder valve in its inoperative position.

4 ly performs automatically the function usually requiring a manual opening of drain cocks on each car reservoir.

However, whilst thus automatically bleeding a train system, the bleeder valve in itself defeats the entire purpose of the reservoir, which is to provide a store of compressed air to operate the brakes'of a car despitethefaccidental uncoupling of air supply. 'Obviously' some means must be added to prevent operation of the bleeder valve in such emergency cases, as opposed to the normal uncoupling of a system.

This function is performed by the protective means P, whose operation is clearly illustrated in Figures 2 and 3. Normally, when the brake pipe carries air under pressure, this air passes through pipe 1 and coupling I4 into the bore of fitting I2. The disc valve rests on the slotted lvalve seat 2| (see Figure 2) of fitting I I, owing to gravity, and the air passes through the slots into the bore of tting II and against-plugIS; The tting II is further provided with a port 36 passing from its bore to a circumferentialgroove 31`in the Vthreaded surface of the tting. A vent 38, adjacent to this groove, pierces the wall of casing 8 holding means P, and opens into chamber I l.

Normally then, air may pass' from the brake pipe C into chamber IIJ. y Y

If, however, the pressure in the brake pipe drops vrapidly owing to accidental uncoupling of the system, air will not pass' from chamber I0 in the'reverse direction to that described, since the disc valve I6 will, against the `force of gravity, be lifted to rest against the smooth valve seat 20 (see Figure 3). Air will not pass thedisc when it is so located, and the air pressure in chamber i0 will remain constant, thereby holding the In the case where it is desired to'release the air from the reservoirs, for example when un- -coupling for shunting operations, the pressure in brake pipe C is not ldecreased so abruptly as in the case of an accidental uncoupling. Consequently the pressure differential operating on disc valve I'6 is not sufficient to cause it to'be lifted against valve seat 2D. In'such cases, then, air will pass out of chamber I0 in a reverse direction to that described, and the automatic bleeder valve will operate when the pressure in the chamber decreases below the critical value.

The critical pressure at which the bleeder valve operates, and the pressure differential required to operate the disc valve, may each be adjustedto `the valve required for best operation in any system by varying the tension of spring 35 or the weight of disc I1.

A unique feature of the system resides in the `provision for operation of the protective means even if it is required to secure theinvention underneath the reservoir instead of on top as shown.

For this purpose, the small extension 40 is provided on the casing 3. This extension has a threaded bore of the same diameter of the bores 'of ttings II and I2, and either a plug similar to I3 or the pipe couplingr I4 may be inserted into this extension. Y Normally this extension is pluggedup. A When the invention is secured' underneath the reservoir, however, the fittings II and I'2 are interchanged and have plugs I3 inserted therein.

` The coupling I4 is inserted in extension 4|) which is provided with a vent 4I leading through casing 8 into the main -bore of means VP. Fitting I2 4I when the fitting is in place. From this groove, a port 44 passes into the interior bore of tting I2 and thus air may pass from the brake pipe into the protective means. As before, the air passes around the disc and through the slotted valve seat into iitting I I. From here the port 36 and circumferential groove 31 allow theair passage to the surface of the fitting, and a vent 45 piercing casing 8 at this point allows the air to enter chamber Ill.

The operation of the protective means may therefore be equally well accomplished when the invention is secured to the bottom of the reservoir.

The casing 8 is further provided with manually operated cock 48 and removable access plate 45, neither of which is essential to operation.

The ttings I I and I2 have suitably slotted outside ends to be engaged by a standard wrench, whilst all plugs and couplings are provided with hexagonal heads or other shapes suitable for easy removing.

The foregoing description shows clearly how the invention has been designed to perform automatically what normally constitutes a lengthy manual operation. Nevertheless, by the addition of protective means, such an automatic bleeding of air brake systems does not decrease the safety factor of the systems.

Although the present showing and description is especially adaptable to the Westinghouse air brake system, it is equally applicable to the newer so-called A-B system. In this last case, the valve of the present invention is inserted in the A-B valve line, whereby the said A-B valve will be bled instead of the reservoir, the result being the same within the particular arrangement of said A-B system. i

It will be understood that the example `of the invention described is to be taken as a preferred embodiment of same, and that various changes as to size, shape and arrangement of parts, or substitution of equivalents may be resorted to without departing from the spirit of the invention.

Having thus described my invention, I claim:

1. In an air brake system having an air-supplying brake pipe and air-storing auxiliary reservoir; in combination, a casing having an air-retaining chamber, a gravity-operated flow-responsive disc valve adapted to normally permit passage of air between said chamber and said brake pipe, whereby said disc valve suspends passage of air when a predetermined maximum outiiow from the chamber is attained; and a pressure-responsive valve comprising a cylinder and piston, the cylinder having at each end a vent open to the atmosphere and to said chamber respectively and having at its side wall a port communicating with the reservoir, said piston slidable inside said cylinder to take a first position over said side port for closing the communication between said chamber and said reservoir and a second position to open the port to said atmosphere vent when the air pressure in the chamber reaches a predetermined minimum value, said piston actuated solely upon pressure variations inside said chamber.

2. In an air brake system having an air-supplying brake pipe and air-storing auxiliary reser- Voir; in combination, a casing having an air-retaining chamber, a gravity-controlled flow-responsive disc valve having communication with said chamber and said brake pipe and adapted to normally permit passage of air, whereby said disc valve suspends passage of air when a predetermined maximum outiiow from the chamber is attained, and a pressure responsive valve comprising a cylinder and piston, the cylinder having at its side wall intermediate these vents terminal vents open respectively to the atmosphere and to said chamber and having a port communicating with the reservoir, a spring positioned in the cylinder between the atmospheric vent thereof and the piston and compressible by the latter, said piston slidable in the cylinder over said port and controlled solely by the chamber air pressure and by the spring pressure, whereby the piston opens the port to the atmosphere vent when the air pressure in said chamber reaches a predetermined minimum value.

3. In an air brake system having an air-supplying brake pipe and air-storing auxiliary reservoir, in combination, a casing having an air-retaining chamber, a pressure-responsive valve comprising cylinder and piston, said cylinder having terminal vents open respectively to the atmosphere and to said chamber and having at its side wall intermediate said vents, a port communicating with the reservoir, Said piston slidable over said port to open the same to said atmospheric vent when the chamber air pressure reaches a predetermined minimum value, anda gravity-operated flow-responsive disc valve having communication with said brake pipe and the chamber whereby air normally passes therebetween, said disc valve movable vertically, interchangeable valve seats limiting disc movement, the lower valve seat having apertures whereby said disc valve closes against the smooth upper valve seat when a predetermined maximum air outflow from the chamber is attained, and said disc valve having interchangeable means for coupling to the brake pipe at the top and bottom of the valve.

GEORGES EMILE BENOIT.

REFERENCES CITED UNITED STATES PATENTS Name Date Strode Dec. 19, 1944 Number 

